The upper house of the Cambodian parliament has unanimously approved legislation to set up a tribunal to try former leaders of the Khmer Rouge regime.

The Khmer Rouge is accused of causing the deaths of more than one million people in the late 1970s.

The legislation has already been passed by the lower house - the national assembly - and will now go to the constitutional council and King Norodom Sihanouk for final approval.

Talks can then begin with the United Nations to work out details of setting up the tribunal in Cambodia, with a mix of foreign and Cambodian prosecutors and judges.

No-one has yet been brought before a court for Khmer Rouge atrocities.

Tricky diplomacy

Senior cabinet minister Sok An, the government's top
negotiator on the trial, told reporters at the Senate he was confidant the law would get UN approval.

"I am optimistic we will come to a resolution," he said. "The date of the trial now depends on these negotiations."

The UN has said Cambodia's judicial system is too weak to hold the trial itself, but has warned the UN will only take part if international standards of justice are met.

Some observers question how committed the government is to a trial.

Prime Minister Hun Sen, himself a former Khmer Rouge member, has warned peace could be threatened if attempts are made to prosecute old Khmer Rouge leaders, most of whom live freely in Cambodia after surrendering to the government.

Last April Cambodia and the UN agreed to hold the tribunal in Cambodia but with UN-appointed prosecutors and judges. It was a compromise between Cambodian officials who
wanted to run the tribunal and the UN which pressed for foreign control.